The following adverse effects have been reported.
Digestive: Gastric bleeding, ulceration, gastritis, diarrhea and cramping, nausea, vomiting.
Endocrine: Gynecomastia (see Precautions), inability to achieve or maintain erection, irregular menses or amenorrhea, post-menopausal bleeding. Carcinoma of the breast has been reported in patients taking Spironolactone but a cause and effect relationship has not been established.
Hypersensitivity: Fever, urticaria, maculopapular or erythematous cutaneous eruptions, anaphylactic reactions, vasculitis.
Nervous System/Psychiatric: Mental confusion, ataxia, headache, drowsiness, lethargy.
Liver Biliary: A very few cases of mixed cholestatic/hepatocellular toxicity, with one reported fatality, have been reported with Spironolactone administration.
Renal: Renal dysfunction (including renal failure).